Method and apparatus for fabricating artificial branches



Sept. 26-, 1967 E. s. GOODRIDGE METHOD AND APPARATUS FOR FABRICAT INGARTIFICAL BRANCHES Filed Mafoh 5, 1965 M M R, mm

M m D R w w w N ATTORNEYS.

United States Patent 3,343,357 METHOD AND APPARATUS FOR FABRICATINGARTIFICIAL BRANCHES Edward S. Goodridge, 23 Broadmoor Road, Scarsdale,NY. 10583 Filed Mar. 3, 1965, Ser. No. 436,828 7 Claims. (CI. 57-24)ABSTRACT OF THE DISCLOSURE Apparatus for the manufacture of artificialbranches comprises a head stock guiding parallel wires which may bepainted. A dispenser for inserting a thermoplastic fiber between thewires is provided. A rotatable tail stock twists the wires to clamp thefibers between the twisted wires and pulls the twisted wire from thehead stock. An induction heating generator is provided to heat the wiressufficiently to soften the thermoplastic fibers and the fibers are thenbent by passing the wires through a sizing die to incline the fibers atan angle to the axis defined by-the twisted wire pair.

This invention relates to a method and apparatus for the fabricationofartificial branches simulating pine, fir and like evergreensparticularly used in the construction of artificial Christmas trees.

At present, branches for artificial trees are made of two wires whichare twisted around each other and containing between the twisted wiresstraight plastic fibers of predetermined lengths. These branches areconstructed in a manner similar to the fabrication of circular brushesfor such applications as bottle brushes, radiator brushes and the like.

There are some disadvantages to the present construction. The presentbranches have their fibers at right angles to the Stem formed by thetwisted wire, which construction does not simulate natural treebranches. The twisted wire can be seen, thus, detracting again from thenatural appearance of the artificial branch. Further, due tomanufacturing tolerances and variations in the manufacturing process,the twisted wire does not exert uniform pressure on all fibers and somemay be displaced and/ or dislodged.

In order to more closely simulate natural branches, the art has deformedthe fibers. For example, the art has subjected the formed branch to heatas by passing the branch through a liquid bath and then deflecting thefibers during cooling. The heating imparts a curvature to the fibersextending them along the axis of the branch. However, this curveddeformation is not an accurate simulation of the natural branch. Perhapsmore important, however, the manufacturing speed and the expense of thistype of added manufacturing stages has been, on the whole, intolerableand has caused many manufacturers to revert to the standardmanufacturing processes with the fibers at right angles to the stern.

It is, therefore, the primary object of this invention to provide animproved method and apparatus for the fabrication of artificial brancheswhich is compatible with continuous processing methods.

It is a further object of this invention to provide an improved methodand apparatus for forming the individual fibers in a manner to controlthe positioning of such fibers within the twisted wire.

It is a further object of this invention to provide an improved methodof manufacturing artificial tree branches having improved accuracy ofcontrol of the process and improved speed of manufacturing. I

In accordance with these objects, there is provided in a preferredembodiment of this invention, equipment for the assembly of a pluralityof heat-deformable fibers be- 3,343,357 Patented Sept. 26, 1967 tweenadjacent wires which are then twisted together to retain the fiberstherebetween. An induction heating coil energized by high frequencycurrent is provided to heat the surface of the twisted wires as theyexit from the twisting apparatus. The heated surface of the wires willsoften the plastic fibers held therebetween. When the fibers are heated,they are immediately passed through a sizing means to incline each fiberat a predetermined angle to the axis of the wires and are cooled whileso inclined to retain this disposition. By this method, the heating ofthe wire can be rapidly accomplished since induction heating will heatthe wire surfaces. The core of the wire may, in some cases, then serveas a heat sink to improve the cooling speed. Thus, manufacturing speedcan be maintained very high. The inclination of the individual fiberstends to lock fibers in position to counteract spring-back of thetwisted wire pair. Further, the control of the heating can be positivelyand accurately controlled so that the painted wires can be utilized inthe process and the heat controlled to melt the plastic material withoutscorching of the painted wire surface.

This invention is more fully described in the following drawing which isa partially sectioned elevation view of apparatus useful in explanationof the method and apparatus of the present invention.

In the figure, there is shown apparatus for manufacturing an artificialbranch containing a twisted wire pair.

The wires 10, 12 are fed respectively from storage spools 14, 16 overpulley 18 to place the wires in juxtaposed relationship. A feed hopper20 is provided which carries a supply of thermoplastic fibers chopped toa predetermined length. Bundles of the fibers are picked up in the teeth22 of the feed wheel 24 and are fed between the wires. The wires and thebundles of fibers frictionally held therebetween are fed through a headstock 26 and are advanced axially as indicated by arrow 28 to a tailstock 30. The relative rotation between head and tail stocks twists thewires to engage the fibers therebetween in a frictional engagement. Thisequipment is very similar to brush forming equipment and is onlydescribed briefly.

In order, however, to form the fibers 32 at an angle to the axis of thetwisted wire pair 34 which constitutes the stem of the branch, there isprovided an induction heating supply source 36 which energizes the coil38 positioned about the wires. The high frequency induction heatingapparatus generates a high frequency magnetic field within the coil toinduce eddy currents in the wire thereby to heat the wire. The heatinduced in the wires is transferred by conduction to the fiberssoftening the fibers. The branch enters a sizing tube 40, the interiorsurface of which is highly polished or coated to reduce frictional dragon the fibers. To prevent rotational tilting of the wires, the tube ispreferably rotated with the wire twisted. The sizing tube deflects thefibers at a predetermined angle to the stern wires. The length of thetube is suflicient so that the wires and plastic are coupledsufliciently to return to a self-supporting state. Forced air may beutilized to cool the wires faster.

The sizing tube 40 may be fabricated of virtually any material such ashighly polished metal or insulator material. If constructed of aninsulator material, the induction coil may be mounted directly over thesizing tube. If made of metal, however, the sizing tube extending intothe coil 42 must be separated therefrom and itself made of anon-conducting material, common to coil core.

On some existing equipment, the tail stock moves in close to the headstock to pick up the ends of a new branch. In such cases, it isdesirable to fabricate the sizing tube and induction heating coil sothat they may be split and removed quickly to clear the tail stock. Thecoil and sizing tube are then closed over the branch as the tail stockmoves out.

The deflection induced in the individual fibers causes the fibers toassume a V-shaped form which assists in locking the fibers in thebranch. Thus, wire springback which is always encountered as thebranches are cut does not result in dislodgement of the fibers quite soreadily. The speed of manufacture can be quite high since the inductionheating coil can induce the desired heat very rapidly and with aprecision of control adaptable for this type of processing. For example,in manufacturing, it is quite common to paint the wires green or brownfor camouflaging or simulation of a tree stern respectively. Withinduction heating, the control can be maintained sufficiently precise sothat the fibers may be heated without, however, scorching of the appliedpaint.

In addition, the induction heating has the distinct advantage that theheat is induced in the skin of the wire. In this way, the body of thewire serves as a heat sink to more rapidly cool the wire after thefibers have been deformed by heat conduction. This distinctly increasesthe potential speeds of manufacture over arrangements which requireheating of the entire fabricated branch including heating the wirethroughout.

For the purposes of illustration, but not by way of limitation, atypical installation might utilize an induction heating source operatingat 3 megacycles and feeding a 3-turn induction coil. With 12 gauge wire,the production speed can be maintained at approximately 3 feet persecond.

Although in the preferred embodiment, I have illustrated the equipmentas comprising the induction heating coil operating in conjunction withthe fabricating equipment, it must be recognized that such illustrationis preferred solely because of manufacturing speeds in typicalinstallations. Finished branches may also be fabricated by passing themthrough the induction heating coil and a sizing tube as an independentmanufacturing step.

This invention may be variously modified and embodied within the scopeof the subjoined claims.

What is claimed is:

1. The method of fabricating an artificial branch having a plurality ofthermoplastic fibers extending transversely to a twisted wire pair andheld therebetween by frictional engagement which comprises heating thewires alone to soften the fibers held therebetween by conduction,deflecting the fibers about said softened material, and cooling thewires and fibers while the fibers are retained in their deflectedpositions.

2. A process fOr producing an artificial tree branch containing formedthermoplastic fibers, comprising feeding fibers of predetermined lengthbetween two wires, twisting the wires to firmly hold the fibers betweensaid wires, heating said twisted wires by induction heating sufficientlyto soften said fibers adjacent to said wire conductively, simultaneouslypassing said heated wire through a sizing means to deflect said fibersat a predetermined angle to axis of the said wires, and cooling saidfibers in angular position prior to leaving said sizing means, cuttingand removing said branch after reaching its predetermined length.

3. An apparatus for producing an artificial tree branch having angularplastic fibers comprising a dispenser for fibers of predeterminedlength, a head stock guiding two parallel wires, means for placingfibers between said wires, a movable tail stock containing a means fortwisting and pulling of said wires containing fibers, an induction workcoil for heating said wires to soften said fibers and tubular sizingmeans surrounding said branch.

4. Apparatus according to claim 3 wherein said sizing means isrotatable.

5. Apparatus according to claim 3 further comprising guiding means forguiding said branch through said coil and sizing means.

6. Apparatus according to claim 3 wherein said sizing means and saidinduction coil are longitudinally split.

7. Apparatus for fabricating artificial branches consisting of at leasttwo central wires twisted together to frictionally hold a plurality ofshort thermoplastic fibers poistioned between said wires, comprisingmeans to heat said wire sufficiently to soften said fibers by heattransfer from said wires to said fibers in proximity to said wires,means to bend said fibers at a predetermined angle to said wires whilesoftened, and means to cool said softened fibers to set said fibers atsaid predetermined angle.

References Cited UNITED STATES PATENTS 2,276,124 3/ 1942 Unger.2,430,748 11/1947 Unger 57-143 XR 2,814,897 12/1957 Hellrich 161223,056,223 10/1962 Crane 161-22 3,084,465 4/ 1963 Hellrich 161--223,109,277 10/ 1963 Raymond et a1 5724 FOREIGN PATENTS 1,311,325 10/1962France.

506,183 5/1939 Great Britain.

618,843 2/ 1949 Great Britain.

702,980 1/ 1954 Great Britain.

FRANK J. COHEN, Primaly Examiner.

D. E. WATKINS, Assistant Examiner.

3. AN APPARATUS FOR PRODUCING AN ARTIFICIAL TREE BRANCH HAVING ANGULR PLASTIC FIBERS COMPRISING A DISPENSER FOR FIBERS OF PREDETERMINED LENGTH, A HEAD STOCK GUIDING TWO PARALLEL WIRES, MEANS FOR PLACING FIBERS BETWEEN SAID WIRES, A MOVABLE TAIL STOCK CONTAINING A MEANS FOR TWISTING AND PULLING OF SAID WIRES CONTAINING FIBERS, AN INDUCTION WORK COIL FOR HEATING SAID WIRES TO SOFTEN SAID FIBERS AND TUBULAR SIZING MEANS SURROUNDING SAID BRANCH. 